Apparatus for making fiber board



July 3, 1928.

Original Filed Dec. 27, 1926 5 Sheets-Sheet l ATTORNEY July 3, 1928. 1,675,667

W. M. SHOEMAKER, JR

APPARATUS FOR MAKING FIBER BOARD 1 VENT R wewyms 7:

ATTORNEY July 3, 1928.

W. M. SHOEMAKER, JR

APPARATUS FOR MAKING FIBER BOARD Original Filed Dec. 27, 1926 3 Sheets-Sheet 3 A TTORNEY Patented July 3, .1928.

UNITED STATES PATENT OFFICE.

WILLIAM H. SHOEMAKER, 53., OF KENNETT SQUARE,. PENNSYLVANIA, ASSIGNOB TO NATIONAL VULCANIZED FIBRE COMPANY, OF WILMINGTON, DELAWARE, A. COR

PORATION OF DELAWARE.

APPARATUS FOR IIAKING FIBER BOARD.

Original application filed December 27, 1926, Serial No. 157,219. Divided and this application filed August 13, 1927.

The present invention relates to the manufacture of fiber sheets or fiber board quite generally known in the trade as vulcanized fiber, in which a plurality of thin sheets of cellulosic material may be united to form a single sheet; or a single sheet may be employed which may be rolled up over a heated drum or cylinder to produce a sheet vof the thickness required.

Heretofore in the manufacture of fiber board the practice has been, as far as I am aware, to subject thin sheets preferably of unsized cotton cellulose paper, to the action of a suitable chemical such as zinc chloride in solution in a suitable solvent by passing the said sheets through such a solution having a strength of about 70 Baum and'at a temperatur ranging from ordinary room temperature to about (1., and conducting the sheets from the said solution directly to and between heated drums or cylinders by means essarily, to both sides thereof simultaneously. v

of which the said sheets are subjected to pressure andheat and union thereof efi'ected to form a single sheet. i

In the manufacture of fiber board it is necessary, after the. impregnation of the sheets with a suitable solution, usually consisting of a suitable chemical in water, that heat be applied thereto. Heretoforc the heated pressure drums or cylinders or other pressure means between which the sheets have been compressed to effect union thereof, have been relied upon for supplying the heat necessary to be applied to the said sheets. By this method the heat is applied dlrectly only to the outer surfaces or sides of the top and bottom plies or sheets of ,the plurality of sheets being united. In order thatt-here may be no question but that the sheet or sheets which enter into the final'product shall have been subjected to the same treatment it is desirable that heat be applied to each sheet separately preferably, though not nec- As a result of so applying the heat and thereby effecting uniformity of application of heat to each sheet a product having umform texture throughout is assured.

The general object, therefore, of the present invention is to provide a novel apparatus Serial no. 212,657.

by the employment of which a. plurality of sheets of cellulosicmaterialmay be united to form a fiber board or fiber sheet having improved structural characteristics and qualities.

Other and further objects of the invention are to provide a novel apparatus by the employment of which both sides'of each of a plurality of sheets of cellulosic material which may be united to form a single sheet may be subjected to the action of heat at a temperature requisite to and for the manufacture of fiber board, or vulcanized fiber as it is generally called in the trade; to provide a novel apparatus wherein and whereby the respective plies or sheets of cellulosic material may each be subjected to the same degree of temperature; to provide a novel apparatus wherein and whereby the plies or sheets which form the interior of the final product shall have been subjected to the same degree of temperature as the sheets forming sheets which are to be united I have discovered that 'a more satisfactory product may be obtained than has been obtainable by the employment of the apparatus heretofore known and employed in the manufacture of fiber board.

In the accompanying drawings I have illustrated one form of apparatus embodying the novel means invented by me for forming one or a plurality of sheets into fiber board or vulcanized fiber "and to which I shall refer in detail in the following description. However, it should be understood that the invention is susceptible of embodiment in apparatus of other forms of construction than that shown and that changes in the details of construction may be made within the scope of the'claims. i

In the drawings:

Fig.1 is a view in side elevation of a portion of a machine or apparatus embodying one form of the invention;

Fig. 2 is a viewpartly in side elevation and partly in longitudinal section of the reand individually the sheets of cellulosic maa fifteen-ply material is to be terial the union of which is to be effected;

Fig. 4 is a view in section taken along the line 4-4 of Fi 3 in a plane at right angles to that in which Fig. 3 is taken; and

Fig. 5 is a view in sectional elevation of a fragmentary portion of the heating means showing more clearly certain details of construction.

Referring to the drawings, one form of the present invention is shown as comprising generally a magazine 10 or supply of plies or sheets of cellulosic material, a tank 11 containing a suitable chemical such aszinc chloride or other suitable metallic salt or other chemical in solution in a suitable solvent, such as water, for impregnating the said sheets, aheating means 12 for the application of heat at the requisite temperature simultaneously to both sides of each of the chemically treated plies or sheets, and a compressing means 13 whereln the plies or sheets are superposed and merged by pressure into a single sheet. This sheet, after the usual subsequent treatment tofwhich my invention does not relate, becomes what is known as fiberboard or vulcanized fiber. The plies or sheets usually consist. of cotton cellulose but, may consist of cellulose obtained from other sources and may also consist of a mixture of cellulose obtained from different vegetable sources.

The magazine 10 preferably is of open frame construction having journals 14 suitably mounted on side bars 14 to rotatably support the rolls 15 of paper (cellulosesheets) which depend in ndmber upon the number of sheets or plies to be used to form the finished product; tl1at is, the fiber board sheet. Thus, if a five-ply material is to be made only five rolls 15 will be used; while if made there will be fifteen rolls 15 in operation. I The solution 16 (preferably of zinc chlo ride or other suitable metal salt) of suitable strength, say around Baum, in the tank 11 is provided in sufiicient quantity to insure the complete immersion of the maximum number of lies or sheets which ma be employed. T e temperature of the so ution as employed. may range from ordinary room temperature to a temperature of about 35 C. One end of the tank 11 is of arc shape as shown in order to prove clearance to permit lateral movement of the ivoted spacing-guide cage 17 toward the eft, and up-' -wardly to a position above the tank 11 to facilitate the insertion or threading plies or sheets 21 betweenthe space guides ofthe b held in spaced substantially parallel relation to each other 'while in and as they pass through the bath or solution 16. The arallel relationship is unimportant but it is importantthat they be held spaced from each other. It will be noted that the u per plies or sheets 21 remain in the said bat or solution for a shorter period than do the successive lower plies or sheets. It follows, therefore, that the speed of travel or movement of the sheet through the bath or 80111- tion must be such as to allow sufficient time for the necessary impregnation of the uppermost sheets. This is a ractical matter. and may be readily control ed or provided for.

To provide for the operation of the cage 17 it is mounted upon a swinging frame 22 which includes lifting arms 23' and a chain hoist 24 whereby it can be swung out of and above the bath 16 for the pur ose previousl stated. p y

la order to effect uniform heating of each ply or sheet 21, after its passage throu h the ath 16 and prior to the union of the s eets, the heating means 12 is provided. In its preferred form the said means consists of a plurality of heating units each of which comprises Iplates 25-and 27 spaced from and in paralle relation to each other to form a wide thin chamber as indicated in Fi 3 and 4 of the drawings. For sup lying a heating medium to the respective c embers formed by the spaced plates 25 and 27, I have provided a tube 30 which is adapted to be supplied with steam from a source not shown. ,The tube 30 may bev located with that steam may be supplied from the tube 30 to the tubes 31 Va ves are provided as indicated at 33 for controlling the admission otsteam from the tube 30 into the tubes 31.

The tubes 31 extend along the sides of the chambers of the respective units as stated and their outer or opposite ends, which are open, terminate in the ends of the-said chamadjoining relation to the tube 80. This steam ers opposite the ends thereof which are in I entering these chambers is condensed so that ultimately they become filled with water which circulates or flows forward therein and escapes through pipes or tubes 34 into a waste tube '35. Tubular connections between the chambers of the respective units and the waste tube 35 are controlled by valves as indicated at 36. The steam is supplied from the tube 30 to the chambers of the respective heating units at a rate sufficient to maintain the liquid within the said units at the temperature requisite to maintain the temperature of said units at a height required in the treatment of the sheets as they pass through the spaces between the said units, as shown in Fig. 2 of the drawings. The temperature to which the said sheets are subjected as they pass between the said heat units ma range from about 38 C. to about 93 C. t may be noted that the upper end of the tube 30 is closed by a plug 37. The upper surface of the plate 25.

of each unit preferably is slightly convex as shown and preferably also the lower surface of the lower plates 27 is slightly concave so that the opposing surfaces of ad oining units are in parallel-relation to each other. The convex upper sides of the respective units afl:'ord or provide more suitable and desirable 30 supporting means over which the respective sheets must travel.

As the respective sheets 21 are conducted through the passageways 38 between the heat units, they contact with'the convex surfaces of the plates, 25-of the. respective units. The adjoining units are located close together, so that the spaces 38 through which the sheets travel, are quite narrow. The heating, in the construction shown, is applied to the lower sides of the respective sheets as they pass through the passageways 38 by conduction from the plates 25 with which they are in contact, while to the opposite sides thereof heat is applied by radiation from the plates 27 of adjoining units. The plates 27 of ad'joining units are so close to the upper sidesof the sheets as they travel through the spaces 38 that the upper side of- GO ing uniform and improved characteristics and qualities as compared with products as heretofore manufactured is the result- Although it is preferred to apply heat to both sides of eachosheet as above described,

it is to be understood that my invention comprehends the application of heat to one side only of each sheet. When the said sheets are thin it is apparent that such application usual]. would accomplish the result desired.

In t e case of sheets of cellulosic material 7 of relatively low absorbtivity, usually charactei ized as hard, it will be found that upon the passage of the same through the solution the outer portions of the opposite sides thereof will besufiiciently impregnated 7 to cause efiicient union thereof upon their passage between the compression cylinders or drums 39 and 40 after having been subjected to the action of the heating means 12 in the manner as hcreinbefore described. It may be that the portions of such sheets between the said outer portions upon the 0pposite sides thereof will not be impregnated, or only partially impregnated, but such a condition will not interfere with the efiicient 35 union of adjoining sheets. All of the sheets which may be passed through the solution and thereafter united will have been subjected to identical treatment and will have substantially the same characteristics.

The heating means 12 as a whole is supported by a frame comprising the angular members 41 located at the opposite ends thereof. These angular members are in turn supported upon other parts of the'frame structure of the machine as indicated. The heating units of the heating means are supported in spaced relation to each other at one side of the said heating means by spaced bars 42 which are supported upon and secured to upwardly extending portions 43 of 'the angular supporting members 41 of the supporting frame. These spacing bars are provided with notches 44in their outer edges. The end portions of the tubes 31 ad oining the tube 30 are located in the notches of one of the spacing bars 42, while projections 45 provided upon the opposite ends of the heatingunit, engage the notches of the other of said spacing bars. 1 c The opposite sides of the said heat units are supported in spaced relation to each other by means of blocks 46 which are secured to bars 47 which aremounted upon the angular 'members41 as shown in the drawings. 7

Preferably the spacing blocks 46 are se-M cured to'- the bars 47 by any suitable fasten ing means, such as nuts and bolts as indicated at 50. One series of the said spacing blocks is located between the tubular outlets 34, "while, the other series thereof is lo cated between projections 51 provided upon the opposite ends of the respective heat units. The projections 45 and 51 are located in opposed relation to each other upon the same end of each heat unit as shown in Fig. 4 of h the drawings. A A

In undergoing the treatment as thus far described impregnation of the sheets with might be effected. As alread 'to the pressure means 13 comprising the heated co-operating ressure drums or cylinders 39 and 40. y reason of the fact that the individual plies Ol SllGQtS have been subjected already to the action of heat by the heating means 12 it is not necessary that these drums ori cylinders 39 and 40 be maintained at as high a temperature as heretofore has been the practice. The sheets to be united are conducted over the drum or cylinder 39, around a portion thereof, and between the same'and the drum or cylinder 40 and thereby subjected to heavy pressure in known manner whereby union thereof is effected to forin a sheet having a combined thickness of the united plies or sheets. The sheet or board formed by the unitin" of the said plies or sheets is led away from the pressure drums as indicated at 52 andfmay be cut into sections of such length as may be desired. These sections then are subjected to the iisual paring out treatment to eifect removal of the chemical with which the respective sheets were impregnated as they moved or passed throu h the solution 16 in the' tank 11. After t e removal of such chemical, usually 'zinc chloride, the .sheets are dried and treated in the-usual way. However, the present invention is not concerned with the means employed in the treatment of thefsheets after they leave the pressure means 13.

In the apparatus heretofore employed in the manufacture of fiber board or. vulcanized fiber the thickness of the sheets constituting the final product which vmight be manufactured has been restricted or limited. Such restriction andflimitation have been due to the fact that the heated pressure drums or cylinders corresponding to those designated 39 and 40. in the drawings have been .relied upon to furnish the heat necessary to be applied to the respective sheets in order that satisfactory union thereof indicated, when the pressure drums or cy inders were relied upon to sup ly the required heat the application thereof has been made only to the outer sides of the outer sheets or plies. It is apparent, therefore, that such an apparatus would berestricted and limited as to the thickness of the fiber board sheet of uniform quality whichinight be produced thereby.

c The apparatus of the present invention is not circumscribed by such restrictions and limitations because. of the application of heat at the required temperature to each sheet of a plurality of sheets which are to be united prior to the bringing of the same together between the pressure cylinders or drums of the compression means by which union thereof is effected.

An important and essential feature of my invention consists in the provision of means for the application of heat to the res ect-ive sheets which are to be united, pre erably simultaneously to both sides of each sheet, after they have been impregnated with the solution 16 of zinc chloride or other suitable chemical and prior to the bringing of the said sheets together and the subjection of the same to pressure by the compression means 13 to effect union thereof.

While I have illustrated a plurality of plies or sheets treated and united to orm a single sheet of fiber board it-will be understood that my invention may be employed in the formation of a fiber board sheet from a single thin s'heetof eellulosic material of proper character by winding the same upon the drum or cylinder 36 to obtain the relllled thickness. The removal of such sheet from the drum or cylinder may be effected in known manner by slitting the same.

This application covers a division of the subject matter disclosed in my application forLetters Patent filed December 27th, 1926, Serial No. 157,219.

Havin thus described my invention, what I cl ai Patent is:

1. An apparatus of the character described comprising, in combination, a bath of impregnating solution, means for feeding a lurality'of sheets of cellulosic material tirough said bath means for super: posing and effecting union of said sheets, and means between said bath and the said in and desire to secure by Letters.

second named means for subjecting said sheetscto the action of heat to etfectuniform heating of said sheets. v

2. An apparatus of the character de scribed comprising, in combination, a bath of impregnating solution, means for feeding a plurality of sheets of cellulosic material through said. bath, means for super-- posing and effecting union Of'8.l(l sheets, and means interposed between said bath and said second named means for applying heat individually to said sheets.

3. An apparatus of the character described comprising, in combination, a bath of impregnating solution, means for feeding a plurality of sheets of cellulosic material through said bath means for superposing said sheets and effecting union thereof, means between the said bath and mild. second named means for applying heat to said sheets, and means for supporting said sheets out of contact with each other during the application of heat thereto. -LA11 apparatus of the character described comprising. in combination, a bath of impregnating solution, means for feeding a plurality of sheets of cellulosic material through said bath, adevice for superposing said sheets and effecting union thereof, a plurality of supports for the said sheets spaced to form a plurality of passageways for the respective sheets. and means for heating each of the said supports to the requisite temperature whereby. each sheet as it moves through the said passageways is subjected to substantially the same heat temperature.

5. An apparatus of the character described comprising, in combination, a bath of impregnating solution, means for feeding a plurality of sheets of cellulosic material through said bath. means for superposing said sheets and effecting union thereof. a plurality of heatunits arranged in spaced relation to each other to form a plurality of passageways through which the individual sheets of cellulosic material are adapted to pass, the said units being located between the said bath of impregnating solution and the said device, and means whereby a heating medium may be circulated through the said units.

6. An apparatus of the character described comprising in combination a tank containing a chemical in solution in water, means for conducting a plurality of sheets of cellulosic material through the saidsolution, and means for applying heat at the requisite temperature individually to the said sheets.

7. An apparatus of the character described, comprising, in combination, a tank containing a chemical in solution in water, means for conducting a plurality of sheets of cellulosic material through the said solution in spaced relation to each other, means for maintaining the said sheets after they have passed through the said solution in spaced relation to each other and means for the application of heat at the requisite '"temperature to each of said sheets.

8. An apparatus of the character described, comprising, in combination, means for impregnating a plurality of sheets of cellulosic material with a suitable chemical, and means-for applying heat at substantially the same requisite temperature simultaneously to both sides of each sheet after such impregnation.

9. An apparatus of the character described comprising, in combination, means for supplying a. plurality of sheets of cellulosic material, means for impregnating the said sheets with a solution of zinc chloride,

means for holding the said sheets in spaced relation to each other while the; are being thus impregnated, compression means for eti'ecting union of said sheets after they have been thus impregnated, and heating means located between the said impregnation means and the said compression means. said heating means including a plurality of heating units supported in close but spaced relation-to each other to form passageways for the respective sheets as they move toward the compression means, one side of each sheet contacting with one of\the heat units as it moves through its passageway and receiving heat therefrom by conduction and the opposite side of said sheet receiving heat by radiation from the adjoining heat unit.

10. An apparatus of the character described comprising, in combination, means for supplying a plurality of sheets of cellulosic material, means for impregnating the said sheets with a solution of zinc chloride, compression means for effecting union of said sheets after they have been thus impregnated, and heating means located between the said impregnation means and the said compression means, said heating means including a plurality of heating units supported in close but spaced relation to each other to form passageways for the respective sheets as they move toward the compression means, one side of each sheet contacting with one of the heat units as it moves through its passageway and receiving heat therefrom by conduction and the opposite side of said sheet receiving heat by radiation from the adjoining heating unit.

11. An apparatus of the character described, comprising, in combination, means for impregnating a 'web of cellulosic material with a suitable chemical for gelatinizing the same, heating means located in cooperative relation to the said impregnating means, the said heating means comprising stationary heated members located in spaced relation to each other, the said space being thereby heated to provide a heating zone, and means for conducting a web of cellulosic material through said impregnating means and through said heating zone.

12. Apparatus for making fiber board comprising means for impregnating a plurality of sheets of cellulosic material with a suitable chemical, means for applying heat at requisite temperature individually and simultaneously to both sides of said sheets after such impregnation, and means for superposing and uniting said sheets.

In testimony that I claim the foregoing as my invention, I have hereunto signed my name this 11th day. of August. 1927.

\VILLIAM M. SHOEMAKER, J R. 

